Coin and disc sorting

ABSTRACT

A high speed coin sorter of the belt type has an elongate plate (8&#39;) along which coins (12) to be sorted are carried in single file by a belt (1) which is driven by a pulley (2). A series of coin deflecting recesses (15 to 18) of hockey stick shape are formed in the upper surface (8) of the plate (8&#39;), and in dependence upon the denomination of a coin, as determined by a coin discriminator (10, 11) positioned in advance of the recesses, the coins are selectively deflected from their straight line paths along the surface (8) by respective solenoid-actuated pins (19 to 22), such that a coin is pressed by the belt into the appropriate deflection recess corresponding to that coin denomination. A shaft encoder (4, 6) is associated with the belt drive pulley (2), and the signals from the encoder are used to track the progress of the coins along the surface (8) from the discriminator to provide a timing signal for projecting the appropriate deflection pin. The encoder signals may be used by the discriminator (10, 11) as the basis of a diameter measurement.

This invention relates to coin or disc sorting equipment andparticularly, but not exclusively, to equipment designed to operate athigh speed.

For convenience the term "coin" will be used hereinafter to include abogus coin or a disc.

Coin sorters have been proposed in which coins in single file arecarried along a smooth horizontal support surface by a belt, the coinsbeing held between the belt and the support surface, and the supportsurface is provided with apertures of different sizes under the path ofthe belt so that coins of different diameters fall through theappropriately sized apertures and are thereby sorted according todiameter.

Such sorters suffer from various disadvantages. Since they sort bydiameter they will not, of course, distinguish between two differentcoins of the same diameter, which is a problem when coins from differentcountries are being handled, or when bogus coins or foreign coins areencountered in a batch of coins nominally of one country.

In one proposal (WO85/05478 of Zimmerman) an attempt is made to sort outbogus or foreign coins before the coins reach the sorting aperture bydeflecting such coins into a reject aperture which is displaced to oneside of the path of the belt in response to a reading from an opticalcoin testing means positioned immediately in advance of the deflectingdevice.

The present sorters of this type are relatively crude since they rely,apart from the rejection device, upon a mechanical testing arrangement.

Such sorters are limited as to the speed of operation, and therefore thenumbers of coins that can be handled per unit time. This is because theyrely largely on gravity to carry the coins though the apertures, that isto take a coin which has reached its corresponding aperture out of thepath of the following coin which may need to proceed to a more distantaperture. As the speed of operation is increased it is possible for thefollowing coin, which is being positively driven by the belt, to collidewith the coin which is in the course of falling through the aperture,and which accordingly is not being driven by the belt.

According to one aspect of the invention a coin sorter comprises asupport surface, a coin transport belt extending in proximity to thesurface and arranged to carry coins trapped between the belt and thesupport surface along the surface, an encoder associated with the beltdrive or belt to provide a signal representative of the position of aportion of the belt, means for feeding coins in serial manner to thebelt, a coin measuring means positioned at a first location in the pathof the belt, and at least one selectively operable coin deflection meanslocated at a second location in the path of the belt downstream of thefirst location, and control means arranged such that, in response to asignal from the coin measuring means that requires the coin to bedeflected by the deflection means, the deflection means is arranged tobe active when the coin reaches the second location as determined fromthe encoder signal.

Thus the progress of the coin along the support surface is monitored bymonitoring the encoder signals, and the deflection means can be arrangedto be activated at the appropriate time.

Since in a high speed coin sorter, in which the aim is to send as manycoins in a given time as possible along the support surface, there willoften be several coins between the first and second locations, it willusually be necessary to ensure that the deflection means is notprematurely activated in order to ensure that only the correct coin isdeflected. That is why the encoder is required to monitor the progressof the coins along the support surface.

Thus, it will be appreciated that positive action is being taken by thedeflection means in response to an earlier measurement which is timed bymonitoring the coins progress, as compared with the passive arrangementof sorters employing sorting apertures.

Usually a series of selectively operable coin deflectors will beprovided which are selectively operated by the control system.

The control system is preferably reprogrammable to enable thedestinations of different coin types in the sorter to be altered asrequired.

According to a second aspect of the invention a coin sorter comprises abelt which is arranged in proximity to a support surface, means forfeeding coins to the belt in single file, the arrangement being suchthat when the belt is driven the coins are trapped between the belt andthe support surface and are carried along the support surface by thefrictional engagement between the belt and the coins, the supportsurface being provided with at least one recess of a depth such that acoin when in the recess is still substantially driven by the belt, therecess being bounded by a deflection wall which is shaped to deflect acoin which is engaged with the deflection wall out of the path of thebelt to a coin receiving means, the arrangement being such that coinsbeing driven by the belt are transversely positioned prior to reachingthe recess, or at the recess, in response to a measurement made by acoin measuring means such that selected coins can be pressed into therecess by the belt for deflection by the deflection wall.

It will be appreciated that with this arrangement the recess providesthe coin deflecting action which was performed by an aperture in theknown arrangement, and since the coin is still being driven by beltwhilst it is in the recess and in the path of the belt there is a muchreduced chance of a collision with the following coin which may beproceeding further along the belt.

The means for selectively positioning the coins transversely of the beltin response to the output of the measuring means is preferably locatedat the recess.

The measuring means can utilise any number of coin measuring techniques,so that the selection of the coins to be deflected can be made ascritical or as course as is required.

The positioning means can comprise a relatively small projection suchthat its inertia can be made small, thereby facilitating rapid movementof the projection to facilitate high speed sorting.

Preferably the projection is in the form of a pin which is retractablesubstantially axially of the support surface by suitable means, such asa solenoid, preferably located beneath the support surface.

In order to sort more than two types of coins the support surface ispreferably formed with a plurality of such recesses, arranged in seriesalong the belt path, and each recess preferably has an associatedpositioning means responsive to the coin measuring means.

The operation of the positioning means in response to the measurementsof the coin measuring means is preferably under the control of aprogrammable control means which can be programmed to arrange for typesof coins as chosen by the user to be deflected at chosen recesses. Insome coinages there can be distinctly different coins having the samevalue, and it is possible to program the control means such that bothtypes of that coin are deflected into the same collection means eventhough their characteristics as measured by the coin measuring means aredifferent.

The coin measuring means can be, for example, an inductive,capacitative, magnetic, optical or any other type or combination ofsensors.

The shape of the deflection wall, as viewed normal to the supportsurface can be chosen to direct the coins in almost any desireddirection away from the path of the belt. This provides substantiallygreater freedom as to the positioning and arrangement of the coinreceiving means as compared with the known sorters in which the coinsfall through apertures in the support surface and accordingly are alldirected roughly downwards.

Each recess is preferably of substantially wedge-shape in transversecross-section and of substantially hockey stick or j-shape as viewed inplan.

The coins can be fed to the belt by any convenient means, convenientlyby a disc feeder supplied from a hopper.

Usually it will not be possible to locate the coin measuring meansclosely adjacent to the coin deflecting recess and it will be desirableto locate the coin measuring means at some position in advance of thecoin deflecting recess. When, as will usually be the case, there areseveral coil deflecting recesses arranged in series, it will bedesirable to operate the respective transverse positioning means inresponse to measurements made by a common coin measuring meanspositioned in advance of all of the coin deflecting recesses. It will bedesirable in these cases to monitor the progress of the coins along thesupport surface using an encoder, in accordance with the first aspect ofthe invention.

An additional advantage of using an encoder to measure the displacementof the belt is that, if desired, the encoder signals can also be used asa basis for measuring the diameter of a coin.

There have, of course, been numerous proposals for coin discriminators.Discriminators which rely upon mechanical tests on coins are generallyseverely limited as to the speed at which they can operate.Discriminators which rely upon the measurement of the electrical andmagnetic properties of the coin tend to be expensive and can place heavydemands upon the computing capacity of a microprocessor unit which isused in conjunction with the measuring transducer to analyse the resultsof the measurements. Many coin discriminators require the coin to beaccurately positioned relative to a datum surface whilst the coin isbeing measured, and such accurate positioning is not easy to producewhen coins are passing through the discriminator at high speed, sincethey tend to bounce off the datum surface, and this difficulty limitsthe accuracy/speed of coin feeding.

Preferably the coin measuring means of a coin sorter in accordance withthe first aspect of the invention comprises a detector adapted torespond to the passage of an identifiable element of the coin past thedetector, and means adapted to compute from the output of the encoderthe longitudinal displacement of the belt which takes place in theperiod between two signals from the coin detector/s.

In some arrangement the two signals can be signals from the samedetector, whereas in other arrangements the two signals are signals fromdifferent detectors.

The identifiable element is preferably an edge of the coin, but it maybe another element, such as the maximum width of the coin when the coinis viewed face on.

The detector preferably utilises electromagnetic waves, preferablyinfra-red light.

The detector preferably comprises a light emitter and a light detectorpositioned on opposite sides of the coin path.

In the most straightforward arrangement the discriminator is arranged tomeasure the coin diameter, the wave emitter and detector beingpositioned such that the direction of propagation of the wavestherebetween is transverse to the coin path and substantially parallelto the plane of the belt. It will be appreciated that, providing thereis no slippage between the belt and the coin, the belt will have beendisplaced by precisely the diameter of the coin in the period betweensuccessive signals from the wave emitter corresponding to the passing ofthe front and rear edges of the coin past the detector.

Since it is only the edge of a coin which is being detected, it ispossible to have only a small spacing between adjacent coins, ascompared with discriminators which measure electrical or magneticcharacteristics of the coins where closely adjacent coins would affectthe measurements; and accordingly the feed rates can be higher than withelectrical or magnetic discriminators.

According to a third aspect of the invention a coin discriminatorcomprises a coin transport belt adapted to convey coins past one or moredetectors, the coins being carried by the friction between the belt andone face of the coin, the detector being adapted to respond to thepassage of an identifiable element of the coin past the detector, andmeans adapted to measure the longitudinal displacement of the belt whichtakes place in the period between two signals from the coin detector/s.

A coin sorter in accordance with the invention will now be described, byway of example only, with reference to the accompanying drawings inwhich:

FIG. 1 is a schematic plan view of the coin sorter;

FIG. 2 is a schematic vertical cross-section of the sorter on the line2--2 of FIG. 1;

FIG. 3 is an enlarged plan view of a portion of the coin sorter showingthe precise shape of one of the identical coin deflecting recesses;

FIG. 4 is a cross-section on the line 4--4 of FIG. 3 but on a yet largerscale; and

FIG. 5 is a similar cross-section but on the line 5--5 of FIG. 3.

With reference to FIGS. 1 and 2, a flexible but substantiallyinextensible belt 1 extends around two pulleys 2 and 3, one pulley 2 ofwhich is fast with the disc 4 of a short encoder on a common shaft 5.Either pulley 2 or 3 is driven by a suitable motor.

A suitable material for the belt is polyurethane reinforced by Kevlar(Trade Mark). In order to minimise changes in the speed of the belt amotor having a high inertia rotor is to be preferred, which may be ofthe external rotor type.

Disc 4 of the shaft encoder is provided in conventional manner with acontinuous series of slits 6, only a few shown in FIG. 1, through whicha light shines to provide a pulse signal on rotation of the disc. Atypical suitable shaft encoder is the Hewlett Packard two channelincremental optical encoder HEDS-5000 series.

The lower run 7 of the belt is arranged closely adjacent to ahorizontal, stationary coin support surface 8 of an elongate plate 8' onwhich the coins can freely slide. Surface 8 can be of, for example,stainless steel, ceramic, or graphite-impregnated nylon.

The lower run 7 of the belt intermediate the pulleys 2, 3 is urgedtowards the surface 8 by a series of suitable spring means, not shown,to ensure that adjacent coins of different thicknesses are each grippedby the belt.

A suitable coin feeding mechanism, not shown, is positioned adjacent topulley 3 and arranged to feed, in known manner, mixed coins in singlefile and spaced apart into the bite 9 so that they are frictionallygripped by the belt 1 and slid along surface 8. The coin feedingmechanism could be of the well known disc type.

The use of the encoder signals as a basis for measuring the diameters ofcoins will now be described, but it sould be understood that, ifdesired, the coins may be tested in other ways.

As shown in FIG. 1, an infra-red diode 10 is positioned to one side ofthe belt 1 and slightly above surface 8. The diode 10 is directedhorizontally at an infra-red detector 11 similarly positioned such thatthe path of infra-red light between the diode 10 and detector 11 ishorizontal, transverse to the path of the coins 12 and at about themid-height of a smallest coin to be measured, thereby ensuring that thebeam of infra-red light will be broken by all coins which are carried bythe belt along surface 8.

The signals from the detector 11 are used to gate pulses from the shaftencoder, the leading edge 13 of the coin causing a fall in the level ofinfra-red light detected by detector 11 which fall is used to open thegate, and the trailing edge of the coin produces a rise in the detectedlight which rise is used to close the gate. Provided that there is noslipping of belt 1 relative to the encoder disc 4, the number of pulseslet through by the gate will correspond to the distance that the belt 1has travelled whilst the coin 12 is passing the detector 11, and so thepulse count is an accurate representation of the coin diameter. Theamount of the pulse count is used to control suitable coin deflectingmeans arranged to direct coins to different batching locations, as willbe described hereafter.

It will be appreciated that since the infra-red beam passes transverselyof the belt 1, the precise transverse position of the coin 12 relativeto the belt does not matter with this measuring technique, and thereforethat, other than surface 8, no datum surface is required. This isdistinct from prior art coin discriminators, and is a considerableadvantage when compared with other detectors which require datumsurfaces. Damaged coins which rest against a datum edge give falsereadings with existing machines.

The coin deflecting means comprises a series of coin deflecting recesses15, 16, 17, 18 formed in surface 8 and having associated respective coindeflecting pins 19, 20, 21, 22 actuated by respective solenoids 23, 24,25, 26 mounted beneath plate 8'. For conenience only four sets of coindeflecting recesses have been shown in FIGS. 1 and 2, but in practiceany number of recesses can be provided to suit the number of coindenominations to be sorted, the length of the plate 8' and belt, beingchosen accordingly. Typically nine recesses are provided.

The shape and action of the coin deflecting recesses will now bedescribed with reference to FIGS. 3 to 5 which show a typical recess 15.For convenience the recesses 15, 16, 17 and 18 are made of identicalshape and size. Recess 15 is of substantially hockey stick or j-shape,comprising a straight limb portion 27 extending parallel to the belt 1and tangentially contiguous with a part-circular, curved deflectionportion 28 which diverges from the belt path.

The retractable pin 19 associated with recess 15 is reciprocable in thereduced diameter upper portion 29 of a bore extending through plate 8'normal to surface 8, the lower bore portion 30 of the bore being adaptedto receive a locating spigot, not shown, on the upper end of therespective solenoid 23 which actuates pin 19.

The coins approaching the series of deflection recesses are roughlypositioned transversely of plate 8', as coin 31 in FIG. 3, by suitableguide means such that in the absence of intervention by one of the pins19-22, the coins would straddle the straight limb portions 27 of thedeflection recesses as they are carried along the surface 8 by belt 1.Pin bore portion 29 breaks through edge surface 32 of recess 15, asshown in FIG. 4, such that when pin 19 is projected above surface 8 bysolenoid 23 a coin 31 will be deflected by pin 19 such that the coin isnot able to straddle the recess portion 27.

As shown in FIG. 4 the recess 15 is defined by edge surface 32 and basalsurface 33, the surfaces 32 and 33 subtending a right angle, and thesurface 32 being inclined at an angle of 7° to the normal to surface 8.The reason for the inclination of surfaces 32 and 33 to surface 8 is toaccommodate a tilted coin, as demonstrated by the coin 34 in FIGS. 3 and5. The coin 34 has been selected for deflection by the recess 15, andaccordingly the pin 19 has been projected to the position indicated inFIG. 4, to move the coin transversely of the plate 8' so that it cannotstraddle the recess portion 27 and the coin 34 has been tilted into therecess by the belt 1, under the force of spring pressure on the belt.

As the coin is carried along recess 15 by belt 1 engagement of the coinwith the curved portion of edge surface 32 will provide the force fordeflecting the coin transversely of the belt, and the coin will leaveplate 8' in the direction indicated in FIG. 3 by the arrow on coin 35from where it will fall into a suitably positioned collection chute, notshown, associated with the recess 15. Thus edge surface 32 constitutes adeflection wall.

It will be appreciated that the collision of a coin with the projectedpin 19 will tend to slow down the coin, but that the frictionalengagement of the belt 1 with the coin will assist in maintaining itsspeed in the direction of the belt path.

The pins 19 to 22 can be of tool steel, and the solenoids 23 to 26 arechosen to have a fast response time.

The general operation of the coin sorter will now be described. A coin12 approaching the coin deflection recesses 15 to 18 is tested by thediscriminator 10, 11, or by some other discriminator/s positioned inadvance of the recesses. The discriminator signal is compared withsuitable reference values held in a memory which are appropriate to thedifferent kinds of coins to be sorted. The comparison will determinewhich of the recesses 15 to 18 is to be used to deflect the coin fromplate 8'. It is then necessary for the software to operate thedeflection pin associated with that recess at the time that theparticular coin is about to reach that recess.

It should be appreciated at this point that, in order to handle a largenumber of coins in a minimum time, several coins will be proceeding infile along the table 8' at the same time, and it is therefore importantthat a deflection pin is not projected prematurely. Accordingly it isnecessary to track the progress of a coin along the surface 8, and theshaft encoder 4, 6 provides the signals for this. Since the distancesalong surface 8 between the discriminator 10, 11 and the deflection pins19 to 22 are known, and since the coins travel substantially withoutslipping relative to the belt, the encoder readings provide an accuraterecord of the coin position along surface 8. Suitable software monitorsthe progress of all of the coins that have passed the discriminator 10,11 and initiates the projection of the appropriate deflecting pin abovesurface 8 just prior to the respective coin reaching the appropriatedeflection recess.

It will be appreciated that the encoder reading is noted at the momentthat the coin is first detected by the coin discriminator 10, 11, andthen a target count of the encoder signals is computed from thedetermination of coin denomination, and the pin is operated when theactual count from the encoder reaches the target count.

In the case of some coin discriminations of some currencies there can betwo coin types having completely different physical characteristics.Since the operation of the deflecting pins and deflection recesses doesnot depend upon the mechanical characteristics of the coin, it ispossible to program the sorter such that both types of coin of the samedenomination are deflected by the same deflection recess.

We claim:
 1. A coin sorter comprising a support surface, a cointransport belt extending in proximity to said surface for carrying coinstrapped between said belt and said support surface along said surface, abelt drive, means for feeding coins in serial manner to said belt, firstand second locations along the path of said belt, a coin measuring meanspositioned at said first location for providing a coin identificationsignal, an encoder associated with said belt drive for providing anencoder output signal representative of the position of a portion ofsaid belt along said path, at least one selectively operable coindeflection means located at said second location which is positioneddownstream of said first location, said control means being arrangedsuch that, in response to a coin identification signal from said coinmeasuring means that requires the coin to be deflected at said secondlocation by said deflection means, said deflection means is arranged tobe active when the coin reaches said second location as determined fromdetecting the occurence of a predetermined change in said encoder outputsignal subsequent to said coin passing said coin measuring means.
 2. Acoin sorter as in claim 1 wherein said coin deflection means comprises adeflection wall bounding a recess in said support surface of a depthsuch that a coin when in said recess is still substantially driven bysaid belt, said deflection wall being shaped to deflect a coin which isengaged with said deflection wall out of said belt path to a coinreceiving means and a selectively operable transverse positioning meansfor transversely positioning selected coins arriving at said recess,whereby selected coins can be pressed into said recess by said belt fordeflection by said deflection wall.
 3. A coin sorter as in claim 2wherein said selectively operable transverse positioning means islocated at said recess.
 4. A coin sorter as in claim 2 wherein saidpositioning means comprises a projection which is retractable below saidsupport surface.
 5. A coin sorter as in claim 4 wherein said projectionis a pin which is retractable substantially normally of said supportsurface by a solenoid.
 6. A coin sorter as in claim 2 wherein saidsupport surface is provided with a plurality of such recesses arrangedin series along said path, and a respective transverse positioning meansis associated with each recess.
 7. A coin sorter as in claim 6 whereineach recess is of substantially wedge-shape in transverse cross-sectionand of substantially hockey stick shape as viewed in plan.
 8. A coinsorter as in claim 6 wherein said control means comprises reprogrammablemeans for enabling the destinations of different coin types in thesorter to be altered.
 9. A coin sorter as in claim 1 wherein said coinmeasuring means is responsive to signals from said encoder which areused as a basis for measuring the diameter of a coin.
 10. A coin sortercomprising a belt which is arranged in proximity to a support surface,means for feeding coins to said belt in single file, the arrangementbeing such that when said belt is driven the coins are trapped betweensaid belt and said support surface and are carried along said supportsurface by the frictional engagement between said belt and the coins, acoin measuring means for measuring coins as they are conveyed by saidbelt along said support surface, a coin receiving means positionedalongside said support surface, the support surface being provided withat least one recess of a depth such that a coin when in the recess isstill driven by the belt, the recess being bounded by a deflection wallwhich is shaped to deflect a coin which is engaged with said deflectionwall out of the path of said belt to said coin receiving means,selectively operable positioning means positioned downstream of saidcoin measuring means and upstream of said recess for selectivelydisplacing said coins transversely of the belt in response to said coinmeasuring means, whereby selected coins are positioned transversely ofsaid belt such that they are pressed into said recess by said belt fordeflection by said deflection wall.